It is routine in the operation of automotive vehicles for an occupant, particularly a driver, to enter the vehicle by opening the door, seating herself or himself, and grasping a portion of the door on its interior side to pull the door to a closed position. In large vehicles, however, particularly in heavy trucks, the door may be swung to an open position in which grasping the door by the occupant for effecting closure may be difficult or awkward.
Devices have been developed in the automotive industry for providing assistance in the closing of pivotally mounted side doors of a vehicle. None of these devices have been found to be suitable in the heavy truck environment. An example of such proposed design may be seen in U.S. Pat. No. 5,002,331, which in particular suffers from the disadvantage occasioned by providing a flexible link between an operator of a door closer mechanism and the door to be closed. This fails to provide the robust connection characteristic desirable in the rugged heavy truck environment, and, furthermore, requires the design of special mechanisms associated with the flexible interconnection that are not commonly available in the automotive and heavy truck environments.